Fluid pump



FLUID PUMP A TTORNEYS.

July l2 1933- J. E. WHITFIELD y2,123,391

FLUID PUMP Filed April 15, 1935 4 Sheets-Sheet; 2

July 12, i938.

- J. E. WHITFIELD 4 2,123,391

FLUID PUMP Filed April 15, 1935 4 sheets-sheet s A TTORNEYS.

July 12, 1938- J. WHITFIELD 2,123,391

' FLUID PUMP Filed April 15, 1955 BY WVJ A TT ORNEYS.

Y v Patented July 12, 1938 UNITED sTATEs iniTENT o'Fr-'lcE Ioseph E. Whitiicld, Grove City, Pa. ppucatlogiisl(lloegzllo. 16,441

The present invention is designed to improve pumps for gaseous, or liquid uids. Generally the object of the invention is to provide a positive displacement pump having alarge capacity for small space and high emciency.

In carrying out the invention a cylinder block is driven rotatively in a stationary case, the rotation of the cylinder opening and closing the cylinder to the inlet and exhaust and the surface relations betweenv the cylinder and case sealing the cylinder. The cylinders areprovided with pistons connected to a stationary crank. Preferably the rotating cylinder block 4 is journaled independently of the sealing surfaces so that wear on the sealing surfaces may be avoided. For some purposes,4 particularly liquid pumping, the crank throwvis made adjustable to vary the capacity of the pump.V The invention further involves details of lubrication. 2o cooling and construction. Features and details Vof theinvention will appear from the specification and claims.

Preferred embodiments of the invention are illustrated in rthe accompanying drawings as i follows:-

Fig. 1 shows a section through the line I-I in Fig. 2. 4

Fig. 2 is a section through the line 2-v-2 in Fig. 1. v A Fig. 3 is'a plan view of the water connection leading to the cooling passages.

Fig.`4 is a section on the line 4-4 in Fig. 2.l

Fig. 5 is a section on the line 5-5 in Fig. 2. Fig. 6 is. aview .of a side portion of the wall of the pump case.V

. Fig. '1 is a central. section on the line 'l--l in Fig. 8 showing a modification.

Fig. 8 is a section on the line 8--3 in Fig. '1.

Fig. 9 is a side elevation of a crank adjust-i.4

ing means. 4

10 is an elevation of the crank. I marks the case. This is made of the side wall 2 having a peripheral wall 3 extending therefrom and a side wall 4 secured to the peripheral wall by screws 5'. The peripheral wall of the case has the braced passage t which may be used fora cooling medium, if desired; The case is provided with an inlet passage 1 and 'an A rotating cylinder block 3 is mounted in the case. It is carried by ball lbearings Il and II'. The ball bearing In is secured ina bore I2 in the side 2 of the case and engages a ring surface I3 on a driving shaft I4. the ring of the ball bear 554 ing'on the shaft being clampedin position-by a screw-threadedring I3a. The ball bearing Il fits on an extension I5 of the side 4 and is arranged in an opening 9a in the cylinder block.

The shaft I4 is provided with a driving means.

such as a drive pulley I4a. The sides of the 6` cylinder block have a labyrinth sealingr surface I6 with the side walls 2 and. 4 and forming a sealing surface. The case has a peripheral sealing surface I1 sealing with the peripheral surface I8 on the block. The ball bearings take Athe ra- 10 dial load on the cylinder block andmaintain the concentricity of the cylinder block. It is possible, therefore, to provide a seal between the surfaces I6 and I1 and avoid a wearing contact between those surfaces. Consequently those l5 surfaces may be maintained in sealing relation'- for a long period of time. Y

Cylinders I8 are arranged radially in the block. Pistons 2B reciprocate in relation to the cylinders. In the embodiment in Figs. 1 and 2 20 which is designed as an air compressor, the outer surfaceI 20a of the piston is curved' to conform to the peripheral surface I'l so that with the piston in its extreme position clearance is practically eliminated.

i 25 The pistons have pins 22 on which connecting f'rods 2i are journaled and the connecting rods extend to pins 23 one. crank ring 2li. A master rod 2 5 is rigid with the ring 24 and operates in` the usual manner. The ring 24 is Journaled 30 on a crank pin 26. f The crank pin extends from a disc 21 and a. crank shaft 28 extends from the disc. The shaft 28 extends through an opening 29 in the case side 4. A `cap 30 is secured by screws 3| on the' 35 end of thel shaft and extends over the side wall 4 at theend of the opening 29. The crank is locked against rotation by the key 32. The screws 3| clamp the disc 21 against the inner bearing ring of the ball bearing II and clamp it 40 in place. The crank, it will -be noted, from t structure is fixed with the case and remains sta tionary s'o that as the cylinder block is rotated the pistons are reciprocated in the cylinder block.

An inlet port 34 extends along. a large por- 45 tion of the peripheral wall 3 so that the cylinders are opened for the intake of air through the larger portion of their suction stroke. A discharge port 35 is provided in the peripheral wall in position to permit discharge after com- 50 pression is sufiicient to effect discharge 'upon the opening of the port. The 'discharge port remains open practically to the extreme outer position Voi the piston so that at the closing of the port the piston is in approximate "sealing relation to the peripheral wall |1 and clearance is practically eliminated.

The lubrication is accomplished through the following mechanism. A small chamber 38 is formed between the cap 30 and the end of the over the end of the crank pin forming a flange for the crank ring. The outer end of the 'bolt' extends through the cap and is provided with a nut 4|. 'Ihis permits the clamping of the cap 40 in place and. assists in clamping the crank in place. A radial passage 42 extends (from the passage 3l to the crank bearing and from vthere the oil reaches the block, thus lubricating the connecting rod bearings, pistons and sealing surfaces. The excess oil is led from the crank chamber by holes 43 in the piston and through an opening 44 in the cylinder block into a seg# mentalgroove 45 (see Fig. 6) in the side wall.

-An opening 48 leads from thesegmental groove through the side wall of the case' where the excess oil may be discharged.

The cylinder block is provided with a cooling cavity 41 which surrounds the cylinders and ports 43 and 4I lead to this cavity at opposite sides of the cylinder block. The shaft I4 has an axial opening Il closed at its outer end in which" there is a plug 53a. 'I'his has a closing portion Il at its outer end, a smaller portion intermediate its ends forming a passage i3. The inner end has a sealing portion I2 and a passage 52a which connects the passage I3 with the passage 43. A radial passage I4 is arranged in the shaft i4 and extends to an annularpassage i! in a ring lla. The ring lla is connected with a passage l1 in a gland 56, and the passage. is connected with a cooling liquid supply (not shown). The return passage 4I from the cavity 41 leads through an opening I3 in the sealing portion l2 of the plug 50a. The

plug lla has a central pori: 59 which leads from the passage i3. A radial passage 80 extends from the port Il and connects with a passage Il in the shaft. The passage 3| leads to an annular pas- `sage32inar`ingl3. Theringisconnected through a radial passage 34 with a discharge outlet 3l. Through Ithis circuit the cylinder block may be cooled. The rings a and 83 are separated by gaskets I3. A follower 61 -is provided for putting pressure on the gaskets and clamping therlngsin place. Ifdesired,aring 63 maybe provided with an annular channel $3 connected through a radial passage with a discharge passage 1| in the gland it the channel Tin this arrangement intercepts any leakage .and discharges it through the passage 1|. 'Ihe gland I3 is clamped to the case by bolts lic extending through flanges lib and ltd (see Fig. 3) and the follower is secured' to a' flange 53d by boltsl .1b extending through a flange 31a on the follower.

It will be noted that the radial arrangement of y the cylinder block in close relation gives a large capacity in a very small space: thai: the utilization of the case as a sealing surface eliminates anymoving valves; that the final position of the piston with relationr to the sealing surface practically eliminates clearance at the discharge; that thslong inlet port assures a full filling of the cylinders even at relatively high speeds; and that the absence of wear on the sealing surfaces at the ends of the cylinders assures an eicient sealing for extended'periods witha minimum of friction. It will be noted in this connection that the radial loads on the cylinder block are quite slight in that none of the pressure walls of the cylinder are subjected to radial pressure so that the thrusts on the cylinder block are merely the frictional thrusts of the piston and except for the slight unbalance that may result in that part of the surface covering the ports the cylinder block is largely balanced. The structure lends itself to simplicity of parts which permits of a rugged construction.

In the modified structure Fig. 7, the pump is shown as arranged forpumping liquids. -It is provided with a case 12 which has side walls 13 and 14,p.nd a peripheral ,wall 15 between the walls 13 and 14 and secured thereto by screws 16.' 'Ihe case has inlet and exhaust passages 11 and 18. A cylinder block 19 largely similar in structure to that of the preferred. construction is mounted in the case. Peripheral sealing rings are arranged within the peripheral wall and have labyrinth sealing surfaces 8| between the ring 80 and the sides of the outer periphery of the cylinder block.

The cylinder block is mounted on ball bearings I2 and 83, the ball bearing 32 being seated in a bore 32a in the case side 13 and on a shoulder 34 of a driving shaft 3l. A drive pulley I3 provides a driving means for the drive shaft. The bearing 83 is arranged in an opening 31 in the cylinder block and on an extension 33 in the case side.

Cylinders Il extend radially and pistons Il op.-

erate in the cylinders. The pistons have pins 3| and connecting rods 82 extend from the pins 3| to pins 93 extending between flanges 94 of`a master rod 95. The crank ring is mounted on a crank pin 91. The crank pin extends from a disc 33 and a shaft 99 extends from the disc. The shaft Il is mounted in an opening IMI in the 'case side. A'worm gear is mounted on the shaftand vlocked therewith by a key Nia. A cap |32 is secured on the outer end of the shaft and a worm -III3 is adapted to rotate the worm gear ill.- The worm is mounted on a shaft |04 journaled in a bracket |15-, 'I'he crank shaft Il is eccentrically mounted with relation to the axis of rotation of the cylinder block so that by swinging the crank on this oil-set shaft center the crank may be brought nearer, or more remote from the axis of the cylinder block and thus provide a greater, or

lesser throw for the crank and consequently a greater or less travel of the piston. The gear III is provided with stops |03 which engage ends |31 of the wormto limit the adjustment of the crank to the desired amount. As the cylinder block rotates, the pistons are reciprocated in the cylinders. The inlet port 11a extends througha large part of the cycle of the cylinder block in which the pistons are moving inwardly, or during the suction stroke. Thev discharge port 13a extends through that part of the travel of the cylinder block in which there is a discharge movement of the piston. As shown in Fig. 7 the crank is adjusted to give the pistons extreme movement so that they reach practically to the outer ends of the cylinders at the nal discharge passage. In the handling of the liquid, however. the throw ofthe piston may be`less than the end'of the cylinder without materially reducing th'e efficiency of the structure. An oil passage |03 extends through the -crank shaft and is connected by a radialpassage |44 withthecrankbearingfmm which the oil is thrown into the cylinder space lubricating the several parts. Oil is admitted through an opening H to a chamber Illia between the`cap |02 and the end of the shaft. A bolt III extends through the passage |08 being of smaller'diameter than the'passage. The bolt is enlarged at the inner end at H2 .to seal the passage and is provided with a cap I I3 forming a flange for the inner end of the crank pin. An oil escape passage H5 leads through the wall of the cylinder block to a segmental passage H6 in the wall of the case and a discharge passage lll leads from the passage I I6 so as to complete the discharge opening.

l. In a fluid pump, the combination of a case having a sealing surface to and from which inlet and outlet ports Vlead said case having an oil discharge passage. therethrough; a cylinder having an exterior wall having a surface adapted to rotatively traverse in sealing relation the sealing surface in the case and ported to open and close to the cylinder the ports in the case; a rotative mounting for the cylinder forming a chamber from which the cylinder leads; a piston in the cylinder; a crank normally fixed with the case; and a connecting rod and bearings between the l having a sealing surface to and from which inlet and outlet ports lead said case having an oil discharge passage therethrough; a cylinder having an exterior wall having a, surface adapted to rotatively traverse in sealing relation the sealing surface in the case and ported to open and close to the cylinder the ports in the case; a rotative mounting for the cylinder forming a chamber from which the cylinder leads; a piston in' the cylinder; a crank normally xed in the case; and means delivering oil to the chamber, said rotative mounting and case-having between them .,a segmental groove forming a part of the oil discharge passage, an opening through the side of the cylinder wall being brought into register with said groove by the rotation of the mounting and being opened and closed by the movement of the piston over said opening. v

A JOSEPH E. WHITFIELD. 

